Improvement in detecters of counterfeit coin



LA. THOMPSON.

DETECTORS 0F COUNTERFEIT com. N.137,935 Patented Feb. 27, 1877.

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JZZ'esZ': INVENTOR ILFETERS. FHOTD-UTHOGRAPMER. WASHINGTON, D C.

UNITED STATES PATENT Qrrron;

JOHN A. THOMPSON, OF CHICAGO, ASSIGNOR TO FRANCIS M. SMITH, OF

LAKE, ILLINOIS.

IMPROVEMENT IN DETECTERS OF COUNTERFEIT COIN.

Specification forming part of Letters Patent No. 187,936, dated February 27, 1877; application filed January 12, 1877.

To all whom it may concern Be it known that I, JOHN A. THOMPSON, of the city of Chicago, in the county of Cook and State of Illinois, have invented a new and useful Improvement in Detecters of Counterfeit Coin, which improvement is fully set forth in the following specification, reference being had to the accompanying drawings.

Figure 1 is a perspective top view of my detecter. Fig. 2 is a side view in the position which it occupies when testing a counterfeit coin. Fig. 3 is a side view in the position it occupies when testing a genuine coin.

The instrument is simply a plate of metal, or other suitable material, (in size and shape similar to an ordinary paper-knife,) with a right-angular bend in or near the middle, as

shown in the drawings. On one side of this right-angular bend or fulcrum the plate is plain, with its outer end, when the instrument is not in use, resting on the table, counter, desk, or other level support. On the other side of the right-angular bend or fulcrum the plate contains slots, as per drawings, for coins ofdifl'erent denominations to be tested. The

slotted end of the plate contains, say, four places for United'States coin, marked respectively ten, twenty, twenty-five, fifty, corresponding to the denominations, in cents, of

the most common United States silver coins, and may contain a slot for any coins, United States or foreign, silver or gold. These slots are of such nicely and properly graduated distances from the right-angular bend or fulcrum, according to metrical rules and tests, that when a genuine coin is placed in its proper receptacle, it barely tips the plate on its angular bend or fulcrum until the slot-ted end rests on the table or other support, as shown in Fig. 3 of the drawings. Consequently, when a counterfeit coin is placed in the slot corresponding to its denomination, it is innnediately detected by its light weight in not tipping the balance, or its greater bulk in filling the slot, as the spurious metal, as is well known, is almost invariably lighter than the genuine, and the coin must therefore be necessarily lighter or larger.

\Vhat I claim as new and as my invention, and desire to secure by Letters Patent, is-

The coin-weighing plate 0 D, provided with the right-angular bend A B, and slotted at' D, substantially as described, and for the purpose set forth.

JOHN A. THOMPSON. Witnesses:

F. J. SnYBoLn, A. J. KIDD. 

